The present invention relates to valves and, more particularly, to an inflation valve for controlling the flow of pressurized gas in the inflation of inflatable devices such as aircraft emergency evacuation slides and rafts.
Inflation valves find extensive use in controlling the flow of a stored pressurized gas to a variety of inflatable devices such as emergency evacuation slides for aircraft, life rafts, crash bags, and the like. For example, U.S. Pat. No. 5,009,249 to Fisher et al. discloses a pressure regulator for regulating an inflatable member such as a slide. The pressure regulator includes a spool valve balanced between a trigger mechanism on one end and a spring on the other. Actuating the trigger mechanism on one end causes the spool valve to be unseated by a first spring and thereby placed in a pressure regulating position by a second spring in opposition to the escaping fluid pressure acting on the valve. The first spring biases the spoon valve to interconnect the outlet with the gas storage, and the second spring regulates the gas flow from storage to outlet in response to pressure change at the outlet.
Similarly, U.S. Pat. No. 4,549,870 to Wass discloses a raft inflation valve having a pin that provides a stop at one end of a spool valve and a spring at the other. Removing the pin allows the spring to urge the spool valve into an open position, thereby enabling inflation of the raft.
In accordance with the present invention, an inflation valve comprises a valve housing having an inner wall, a cylindrical inner chamber terminating in a gas outlet, and a gas inlet bore providing fluid communication between the inner chamber and a pressurized gas source. A piston enclosed in the inner chamber comprises at one end a head directed toward the gas outlet and at the opposite end a valve actuator connector. The piston further comprises a gas inlet seal, positioned between the head and the actuator connector, that releasably seals the gas inlet bore from the inner chamber when the piston is in a normal non-actuated position. A valve actuator connected to the actuator connector operates to pull the piston, thereby moving the gas inlet seal away from the gas inlet bore and putting the inner chamber in fluid communication with the gas inlet bore and pressurized gas source. A regulating spring disposed within the inner chamber close to the actuator connector is compressible by the force of pressure exerted by gas contained within the inner chamber and gas inlet bore and operates to position the piston to control or regulate the outlet pressure, returning the piston toward its normal non-actuated position as the gas in the inner chamber exits via the gas outlet.